This research is concerned with (a) solution conformational determinations of cyclic peptides and (b) determination of the conformations in solution of certain proteolytic enzymes (elastase and collagenase). The work under (a) will involve circular dichroism measurements, proton magnetic resonance spectroscopy, C13 magnetic resonance spectroscopy, and fluorescence measurements. The work under (b) is aimed at delineating the active site and substrate interactions of these enzymes. BIBLIOGRAPHIC REFERENCES: C. M. Deber, V. Madison, and E. R. Blout, "Why Cyclic Peptides", Accts. Chem. Res., 9, 106 (1976). C.-A. Bauer, R. C. Thompson, and E. R. Blout, "The Active Centers of Streptomyces griseus Protease 3 and alpha-chymotrypsin Enzyme-Substrate Interactions Remote from the Scissile Bond," Biochemistry, 15, 1291 (1976).